VIDEO FEATURE: THE ORIGINAL TOP OF THE FOOD CHAIN - A/STOCK CHALLENGE

They were the original alpha class. Big block engines, four-speed transmissions and a penchant for doing whatever they wanted. These beasts, although no longer at the top of Stock Eliminator is still very much ornery, and quite the animal to tame. Go behind the scenes at the Chevrolet Performance U.S. Nationals in Indianapolis on Thursday as these high horsepower beasts battle for A/Stock supremacy.